The shoddy soldering work and re-use of old parts give this a typical home-brew character. This was probably done by a a radio amateur who did not have the original power supply and cooked something up so he could link the B2 set into whatever power supply he was using. Common practice in the radio amateur world.

I had seen many 3mkII , there is an other point , b2 mains transformer
seems to burn easy , guess isolation is’nt very good , many psu
are faultly , and a previous owner had probably finded this problem , with a burned
psu , of you search for rewinding the transformer , or you adapt yourself
i think he has cutted the burned psu and made this adaptor .
It was what i had wrotten in post 4 .
Pierre

Vendor states his father was not an amateur radio ham and never had an interest in radios. He stated this was amongst his fathers military kit that he brought home after the war and it never came out of the loft.

His father was a RAF wireless operator during the war and worked out of Italy and Albania.

__________________Collecting Interests are;All items related to the SICHERHEITSPOLIZEI/SD with a particular focus on Identity Credentials

Hello
When the war was over , in 1946 soe was disabended, and all
the radios sets where given for a bargain price at RSGB
radio society of great britain , but only to licences radio ham
for some Ł, nearly all the remaining B2 are containers ones
all of them with 45 date right in measuring instrument ,
The serial numbers are high 89.000 to 90.000.
I had seen a film On the kon-tiki raft , a norvegian was using his
B2 set with the hand generator
Following was i describe here up , one of the previous owner must
had a ham licence to be allow to buy the set, then may be later resold
to somebody else .
Normaly the sets that are parachuted , stays in foreign land and don’t
come back to UK
Pierre